Janeway has more experience with the Borg than anyone else in Starfleet. Her going makes more sense than you're admitting.
Besides, if she sent a gaggle of hapless nobodies over in her sted, wouldn't things have proceeded largely identically, except for the probability that Hapless Nobody Queen wouldn't have been able to stall the Borg at the critical moment, thus dooming Earth?
Besides, if she sent a gaggle of hapless nobodies over in her sted, wouldn't things have proceeded largely identically, except for the probability that Hapless Nobody Queen wouldn't have been able to stall the Borg at the critical moment, thus dooming Earth?